“Electrical Wavelength-Tunable Actively Mode-Locked Fiber Ring Laser with a Linearly Chirped Fiber Bragg Grating” by Li et Chan published in IEEE PHOTONICS TECHNOLOGY LETTERS, VOL. 10, NO. 6, JUNE 1998 799 describes a tunable mode locked laser in which changes in the frequency of variations in absorption in the laser cavity result in changes in cavity length. In turn, changes in cavity length result in changes in the wavelength of the light emitted by the laser. One manner of achieving this result is to reflect the light in the cavity with a chirped fiber Bragg grating (FBG) in which different wavelengths are reflected at different longitudinal positions along the FBG.
In some applications, there is a need to synchronize two or more such lasers. More generally, there is a need to synchronize two or more dispersion-tuned actively mode-locked lasers (DTAML). In these lasers, dispersion is used to tune the mode-locked lasers. The use of FBGs is an example of such dispersion tuning, but any other manner of creating a different round trip travel time of a laser pulse in a laser cavity as a function of wavelength through the use of dispersion is usable. There are several issues in synchronization of such laser oscillators. The two main issues are 1) adjusting the delay between the outputs of both lasers so their pulses overlap and 2) having both lasers operate at exactly the same repetition rate. Since DTAML are actively model-locked, the timing of the output pulses is determined by the electronic signals driving the mode locker.
Against this background, there exists a need in the industry to provide synchronize tunable model-locked lasers. An object of the present invention is therefore to provide such lasers.